/Engine/Source/Runtime/Slate/Public/Framework/Text/RichTextMarkupProcessing.h
Write the provided array of line and run info, producing an output string containing the markup needed to persist the run layouts
virtual void Write ( const [TArray](API\Runtime\Core\Containers\TArray)< [FRichTextLine](API\Runtime\Slate\Framework\Text\IRichTextMarkupWriter\FRichTextLine) > & InLines, [FString](API\Runtime\Core\Containers\FString) & Output )